code: def test_ablation_flip_fails_without_pred_key(self):
      ex = {"sentence": "this long movie is terrible"}
      with self.assertRaises(AssertionError):
          self.ablation_flip.generate(
              ex, self.classification_model, None, None
          )
  
imports: from collections.abc import Iterable, Iterator
  from absl.testing import absltest
  from lit_nlp.api import types
  from lit_nlp.components import ablation_flip
  from lit_nlp.examples.models import glue_models
  import numpy
  from lit_nlp.lib import file_cache
label_desc: Use image node_id 12 for calling the ModelBasedAblationFlipTest obj's underlying member method code with example usage: obj.test_ablation_flip_fails_without_pred_key() without return types